Processing Method of A Non-PVA Hollow Yarn and The Tubular Fabric

ABSTRACT

The invention discloses the processing method of a non-PVA fiber hollow yarn and the tubular fabric. The fiber shall include filament yarn, staple yarn and ribbon. The processing method applies degradable fiber which is controllable in degradation conditions and has none formaldehyde residue to produce hollow yarn, in contrast with conventional soluble Vinylon hollow yarn, which is environmentally friendly and cheap while has low shrinkage and distinct hollow effect as can be made into high density textile and single yarn textile through sizing process. Furthermore, the tubular fabric as described in this invention spinned with the non-PVA fiber hollow yarn is feature with lightness, fluffy sense, warmth, moisture absorption and softness.

BACKGROUND OF THE INVENTION

The invention relates to the technology field of spinning, especially to the processing method of a non-PVA hollow yarn and the tubular fabric.

Textile industry always creates good things to our life. The assortment and quality of yarn is the basis of quality of textile products. The basic assurance for enterprise survival, development and prosperity of textile markets is to output yarns of new varieties and good qualities as to meet and promote the quality of textile products and ultimately to bring the companies to be competitive in the market.

Hollow yarn carries a special hollow structure which brings advantages of lightness and fluffy sense, warmth, moisture absorption, softness and so on as well as excellent usability of the product. With broad market prospects, it mainly applies for knitted underwear, high-class towel, socks, gloves and the other applications.

Conventional hollow yarn is proceed with technology of covering yarn while the original yarn is characterized with bilayer structure. It cores with soluble PVA fiber or soluble PVA staple fiber and uses cotton or other fibers as outer coating to make into yarn for spinning. Then, PVA yarn core is dissolved by leaving holes in the center of yarn after post-processing of dissolution to form a yarn with annular hollow structure. A new 100% hollow yarn is very light and soft and characterizes new performances for cotton textiles. For instances:

1. Warmth and warm feeling. Generally, warmth means thermal insulation. As air is one of the excellent thermal insulation media, theoretically, the thermal capacity is higher when the still air volume in the fiber is higher. Hollow yarn has excellent warmth capacity as the yarn core is substituted by air with amount of still air in the yarn.

2. Excellent moisture absorption and quick drying. The air permeability of textile depends on the spacing dimension and quantity. Obviously, bigger and more spacing in the textile will bring higher permeability. Hollow yarn has excellent wicking that moisture on the skin surface will be transmitted in liquid to the textile through wicking and be evaporated from the surface of textile into the air for the purpose of wicking and quick drying.

3. Light and fluffy. As there is amount of air in the center, hollow yarn of same size is rather fluffy and lighter than conventional yarn.

4. Soft. Under external force like washing or kneading, the hollow structure will not be destroyed but still maintain the original soft feeling.

To develop soft hollow yarn with soluble fiber is a new technology created in these a few years. Japan has made great succeed in development and research of cotton hollow yarn being on the world-leading level on this project. It is reported that, Japan companies Kurabo and Kuroray cooperates to develop cotton hollow yarn through friction spinning technology and soluble Vinylon fiber. AliAbar Merati and Masaaki Okamura take effort to study the influence of the content of soluble PVA on the strength character of hollow yarn and the variation of yarn diameter and variation factor under axial and lateral force. Researches show that, there is no obvious variation on strength but better elongation performance when compare hollow yarn and conventional yarn. However, China just starts the research on this project while mainly uses Vinylon staple fiber of higher solution temperature to develop hollow yarn. Professor Mingzhen Chen from Wuhan Technology College uses Sirofil spinning technology with fine soluble Vinylon staple fiber to spin wool hollow yarn and conducts tests to textile products made of wool hollow yarn on their mechanical performance, permeability and moisture absorption. Professor Huiying Ma from Tianjin Industrial University develops hollow yarn with conventional ring spinning technology, mainly studying on the strength variation of yarn during vinylon dissolving and product performances.

For the above situations, we found that foreign countries mainly use soluble Vinylon fiber to develop hollow yarn, but in domestic we mainly use soluble Vinylon s fiber. However, there are a few issues as shown below for soluble Vinylon which has limited the popularity and development of hollow yarn. 1. Soluble Vinylon fiber is polyvinyl formal which cannot be fully dissolved in hot water while the macromolecule inside is non-degradable. Besides, formaldehyde is often found in the residue, which is forbidden in some field in Europe and America at early stage; 2. Soluble Vinlyon fiber is expensive; 3. Its dissolution process in hot water can be specified as: The fiber gets through swelling, shrinking, fragmenting and diffusion dissolution in hot water. However, there is no hollow effect eventually since the shrinkage of hollow area is distinct when the shrinkage ratio is high and the shrinkage is over performed; 4. Covering yarn with Vinylon cannot get into sizing process as result of the shrinkage and dissolution of soluble Vinylon fiber in hot water, thus, they are only suitable for low density or two fold textile.

BRIEF SUMMARY OF THE INVENTION

This invent aims to provide processing methods of a non-PVA fiber hollow yarn specific to disadvantages of current technology. The fiber should include filament yarn, staple yarn and ribbon. The processing method of non-PVA hollow yarn applies degradable fiber which is controllable in degradation conditions and has none formaldehyde residue to produce cheap, low shrinkage covering yarn with distinct hollow effect that can be made into high density textile and single yarn textile through sizing process.

This invention also aims to provide a kind of tubular fabric which is characterized with lightness, fluffy sense, warmth, moisture absorption and softness.

To reach the above aims, the following technology solution will help to realize the invention.

The processing method of a non-PVA fiber hollow yarn should include the following processes:

Process degradable fiber which is controllable in degradation condition and has none formaldehyde residue. The fiber should include filament yarn, staple yarn and ribbon;

Cover the degradable fiber which is controllable in degradation condition and has none formaldehyde residue with outer fiber through open-end-spinning or non-open-end-spinning. The outer fiber should include various staple fibers to produce covering yarn;

Dissolve the degradable fiber which is controllable in degradation condition and has none formaldehyde residue in the covering yarn to produce hollow yarn;

Among them, process a shall include preparation of alkaline degradation section, preparation of blended spinning melts and spinning procedure. In process c, the dissolution temperature shall be 20-100° C., the alkaline concentration shall be 1.5-30 g/l, within 20 min-24 hours.

The preparation of alkaline degradation section in process a shall include the following steps: Add sodium sulfonate—isophthalic acid glycol ester at total polymer weight of 1-20% and isophthalic acid at total polymer weight of 1-20% during polymerization process of polyester staple fiber, beat and stir while heating up to 230-250° C. Then move to reactor and again add in ethylene glycol at total polymer weight of 1-20% to dilute, and cool down to 200-210° C.; Add in polyethylene glycol at molecular weight of 4000-6000 which takes 1-20% of the total weight of polymer. Complete the addition of polyethylene glycol within 40-50 min while keep stirring. Under room temperature, heat up to 230-250° C. and make the mixture to polymerize in vacuum condition. Then the alkaline degradation section after polymerization and perform the cast stripping, cooling, grain cutting, drying and selection procedures. The intrinsic viscosity of alkaline degradation section shall be 0.55-0.75.

The preparation of blended spinning melt in process a shall include the following steps: Put the above alkaline degradationnrr section into stainless-steel degradation kettle and stir to form spinning melt while heating. During the preparation of spinning melt, blend degradable material into it. The proportion by weight of alkaline degradation polymer and degradable material shall be 100:0-60:40. Part of the degradable material will be filtered or dissolved to form microvoid on the fiber surface along the axes.

The degradable material shall include porous agent Kaolin, degradable silicon dioxide, degradable barium sulfate, degradable calcium carbonate or water-soluble polyester.

A tubular fabric is spinned with hollow yarn produced according to claims 1 to 4.

The beneficial effects of the invention are: The processing method of a non-PVA fiber hollow yarn uses degradable fiber which is controllable in degradation condition and has none formaldehyde residue to produce covering yarn. By comparing with conventional water-soluble Vinylon hollow yarn, hollow yarn prepared with this method is featured as following: 1. The fiber in it is dissolved under certain alkaline condition as chemical dissolution, there is none residue and it is environmental friendly; 2. Cheap. There is no necessary to apply additional dissolving process with natural dissolution instead in the pre-processing of the textile; 3. The fiber is processed under certain alkaline condition in result of low shrinkage, while the direct dissolution has no impact on the flatness of the textile to produce distinct hollow area; 4. The degradable fiber which is controllable in degradation condition and has none formaldehyde residue is not dissolute in alkali-free suspension, thus sizing process is applicable for hollow yarn of degradable fiber which is controllable in degradation condition and has none formaldehyde residue, that is to say, applicable for high-density and single yarn textile.

The other effect of this invention is that: The tubular fabric as described in this invention spinned with the above non-PVA fiber hollow yarn is featured with lightness, fluffy sense, warmth, moisture absorption and softness.

DETAILED DESCRIPTION OF THE INVENTION

Below is the description of specific implementation of this invention.

The processing method of a non-PVA fiber hollow yarn includes the following steps:

a. Process degradable fiber which is controllable in degradation condition and has none formaldehyde residue. The fiber shall include filament yarn, staple yarn and ribbon;

b. Cover the degradable fiber which is controllable in degradation condition and has none formaldehyde residue with outer fiber through open-end-spinning or non-open-end-spinning. The outer fiber should include various staple fibers to produce covering yarn;

c. Dissolve the degradable fiber which is controllable in degradation condition and has none formaldehyde residue in the covering yarn to produce hollow yarn;

Among them, process a shall include preparation of alkaline degradation section, preparation of blended spinning melts and spinning procedure. In process c, the dissolution temperature shall be 20-100° C., the alkaline concentration shall be 1.5-30 g/l, within 20 min-24 hours.

The preparation of alkaline degradation section in process a shall include the following steps: Add sodium sulfonate—isophthalic acid glycol ester at total polymer weight of 1-20% and isophthalic acid at total polymer weight of 1-20% during polymerization process of polyester staple fiber, beat and stir while heating up to 230-250° C. Then move to reactor and again add in ethylene glycol at total polymer weight of 1-20% to dilute, and cool down to 200-210° C.; Add in polyethylene glycol at molecular weight of 4000-6000 which takes 1-20% of the total weight of polymer. Complete the addition of polyethylene glycol within 40-50 min while keep stirring. Under room temperature, heat up to 230-250° C. and make the mixture to polymerize in vacuum condition. Then the alkaline degradation section after polymerization and perform the cast stripping, cooling, grain cutting, drying and selection procedures. The intrinsic viscosity of alkaline degradation section shall be 0.55-0.75.

The preparation of blended spinning melt in process a shall include the following steps: Put the above alkaline degradationnrr section into stainless-steel degradation kettle and stir to form spinning melt while heating. During the preparation of spinning melt, blend degradable material into it. The proportion by weight of alkaline degradation polymer and degradable material shall be 100:0-60:40. Part of the degradable material will be filtered or dissolved to form microvoid on the fiber surface along the axes.

The degradable material shall include porous agent Kaolin, degradable silicon dioxide, degradable barium sulfate, degradable calcium carbonate or water-soluble polyester.

Production of non-PVA fiber hollow yarn. The first step is to produce covering yarn which is combined by two different kinds of fibers separately on outer layer and core layer when the outer fiber tightly covers on degradable fiber which is controllable in degradation condition and has none formaldehyde residue by applying open-end-spinning or non-open-end-spinning which includes conventional ring spinning, siro spinning, compact spinning, murata vortex spinning, friction spinning and the other. For instance, a modified ring spinning frame for non-open-end spinning can be used to produce covering yarn. The degradable fiber which is controllable in degradation condition and has none formaldehyde residue runs through yarn guides and directly feeds into front roller through integral edger instead of through the collector of front roller. The covering cotton fiber should cover on the surface of degradable fiber which is controllable in degradation condition and has none formaldehyde residue by conventional spinning way. When the back end of cotton fiber leaves the plier of front roller, the tension generated is decreased, but the degradable fiber which is controllable in degradation condition and has none formaldehyde residue still remains in the position between winding points of the guide while keeping its tension, therefore, the cotton fiber is covered on the surface of the yarn core. Then twist and wind the yarn to complete the spinning process.

A tubular fabric is spinned with non-PVA fiber hollow yarn processed according to the above method. Since hollow yarn fabric is made by covering yarn, before clearing degradable non-PVA fiber, the fabric shall not be a genuine hollow yarn fabric, instead, it should be conducted with a series of processes, including dissolution, to dissolve degradable non-PVA fiber from the hollow yarn.

A tubular fabric can be produced through regular spinning process, that is to spin the textile with covering yarn, or go through sizing before spinning into textile including knitting fabric and woven fabric.

The dissolution process of covering yarn fabric shall depends on various fabric types and processing conditions. According to product requirements of covering yarn fiber, the dissolution condition is controllable and has a wide range. For instance, the temperature shall be 20-100° C., the alkali concentration shall be 1.5-30 g/l, within 20 min-24 hours.

The above content is only about the better implementation cases of the invent. General technicians of this field may make modifications to the specific implementation way or application range according to the concept of the invention. The content in this description shall not be interpreted as a restriction of the invention. 

What is claimed is:
 1. Processing method of non-PVA fiber hollow yarn is featured with the following steps: a. Process degradable fiber which is controllable in degradation condition and has none formaldehyde residue. The fiber should include filament yarn, staple yarn and ribbon; b. Cover the degradable fiber which is controllable in degradation condition and has none formaldehyde residue with outer fiber through open-end-spinning or non-open-end-spinning. The outer fiber should include various staple fibers to produce covering yarn; c. Dissolve the degradable fiber which is controllable in degradation condition and has none formaldehyde residue in the covering yarn to produce hollow yarn; Among them, process a shall include preparation of alkaline degradation section, preparation of blended spinning melts and spinning procedure. In process c, the dissolution temperature shall be 20-100° C., the alkaline concentration shall be 1.5-30 g/l, within 20 min-24 hours.
 2. According to claim 1, the processing method of non-PVA fiber hollow yarn is featured with that the preparation of alkaline degradation section in process a shall include the following steps: Add sodium sulfonate—isophthalic acid glycol ester at total polymer weight of 1-20% and isophthalic acid at total polymer weight of 1-20% during polymerization process of polyester staple fiber, beat and stir while heating up to 230-250° C. Then move to reactor and again add in ethylene glycol at total polymer weight of 1-20% to dilute, and cool down to 200-210° C.; Add in polyethylene glycol at molecular weight of 4000-6000 which takes 1-20% of the total weight of polymer. Complete the addition of polyethylene glycol within 40-50 min while keep stirring. Under room temperature, heat up to 230-250° C. and make the mixture to polymerize in vacuum condition. Then the alkaline degradation section after polymerization and perform the cast stripping, cooling, grain cutting, drying and selection procedures. The intrinsic viscosity of alkaline degradation section shall be 0.55-0.75.
 3. According to claim 2, the processing method of non-PVA fiber hollow yarn is featured with that the preparation of blended spinning melt in process a shall include the following steps: Put the above alkaline degradationnrr section into stainless-steel degradation kettle and stir to form spinning melt while heating. During the preparation of spinning melt, blend degradable material into it. The proportion by weight of alkaline degradation polymer and degradable material shall be 100:0-60:40. Part of the degradable material will be filtered or dissolved to form microvoid on the fiber surface along the axes.
 4. According to claim 2, the processing method of non-PVA fiber hollow yarn is featured with that the degradable material shall include porous agent Kaolin, degradable silicon dioxide, degradable barium sulfate, degradable calcium carbonate or water-soluble polyester.
 5. A tubular fabric is featured with that it shall be spinned with hollow yarn processed according to claims 1 to
 4. 